Ship s hull



M. l. ANDREA June 9, 19N

SHIP'S HULL Original Filed Ilay 12, 1967 QWGN@ E d: S .E

INVENTOR .ESQ

Mario IAndrea "Y @9W a gaf' AGENT United States Patent O ABSTRACT F THEDISCLOSURE Frames with straight [vertical] upper members and V- shapedlower members, the V-angle from stem aft increasing uniformly from about0 to about 180, re-

maining at about 180, and then decreasing uniformly towards 0.

This invention described herein may be manufactured and used by or forthe Government of the United States for governmental purposes withoutthe payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to a ships hull, andmore partcularly to an economical, straight-framed hull for cargo shipsand the like.

The hulls of cargo ships and the like presently are constructed inaccordance with various forms or series that have been developed duringthe last several decades. As is well known, these series utilizeindividually curved frames and plates which are inherently expensive tofabricate and fit. Although there have been some efforts to constructhulls with straight frames and flat plates, such hulls have not beenwidely accepted, because the savings in construction have not offset theincreased cost of operating these less efficient hulls.

SUMMARY OF THE INVENTION This invention provides a straight-framed hullwhich is highly economical to construct and yet suficiently economicalto operate that a considerable savings in total cost is realized. Inaccordance with the principles of the invention, the hull is constructedwith straight V-frames, and the V-angle from the stem aft is uniformlyincreased and about 0 to about 180, maintained at about 180, and thenuniformly decreased towards 0. This controlled and uniform variation ofthe V-angle provides at once an economical and ecient hull. The hull iseconomical to construct because a large proportion of the frames andplates are identical or interchangeable, permitting mass productionthereof; and the hull is efficient because the bow and stern portionsare helical surfaces which merge smoothly into the middle body portionof the hull.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a hullembodying the principles of this invention;

FIG. 2 is a body plan of the hull of FIG. 1;

FIG. 3 is a perspective view of a plate for the bow of the hull; and

FIG. 4 is a perspective view of a plate for the stern.

DESCRIPTION OF THE PREFERRED EMBODIMENT The lines 0-20 in FIGS. 1 and 2represent the intersections of twenty-one equally spaced transverseplanes or stations with a hull constructed in accordance with thisinvention. The lines 0-10 in the right half of FIG. 2 are the fore bodylines, while the lines 10-20 in the left hall: are the after body lines,in accordance with common naval architectural practice. The load waterline is designated as LWL- LWL In accordance with this invention, all ofthe frames have straight [vertical] upper members and straight, V-shaped lower members, as shown by lines 0-20. In addition, the V-anglesof consecutive, equally spaced frames from the steam aft increase by arst constant angular increment from about 0 to about [w] 180, as shownby lines 0-6; remain at about 180 for one or more frames, as desired, asillustrated by lines 7-13; and then decrease by a second constantangular increment from about towards 0, as shown by lines 14-20. Theframes from stations 0-14 are joined along a horizontal keel 30, whilethe frames from stations 14-20 are joined along an after keel 32 whichis illustrated as having a uniform slope, although it could equally wellbe horizontal or sloped in a nonuniform manner.

The above-described framing of this invention provides a hull havinghelical bow and stern surfaces 34 and 36. It may be recalled that ahelical surface is generated by a line which is rotated about an endthat simultaneously is translated along a directrix. A screw is a commonexample of a helical surface. Since the lower portions of lines 0-6 areequally spaced along the keel 30, and evenly rotated thereabout, itfollows that the framing surface defined thereby is helical. Hence, thebow portion of the hull comprises two quarter-turn, oppositely rotatedhelical surfaces 34 having a common vertical edge or stem, shown as line0, and a common horizontal directrix or keel 30.

In similar manner, the lines 14-20, which are evenly spaced along androtated about the after keel 32, define two oppositely rotated helicalstern surfaces 36 having the after keel as a common edge. These helicalstern surfaces, which are illustrated as about one-sixth turn each,terminate in a flat transom stern, shown by line 20. The amount ofrotation or twist of the helical stern surfaces may of course bemodified to suit any selected stern configuration. It is to be notedthat the lengths of the lower frame members from stations 14-20 aresuccessively decreased to the length of the lower member of frame 20, soas to form a smoothly curved stern chine line 38.

As mentioned hereinbefore, the helical bow and stem surfaces 34, 36 ofthis invention provide a highly economical hull. It will be observedthat the lower members of the frames from station 0-14 are all straight,and of the same length. Accordingly, these members may be fabricated andfitted in an economical, mass-produced manner. From stations 14-20, thelower frame members are straight, but of successively decreasing length,and therefore require a small amount of individual cutting and fitting.The upper members of all of the frames from stations 0-20 are straight,and the upper members from stations 6-14 are equal in length. Theseupper members are preferably welded or otherwise joined to theirrespective lower members. In this manner, the framing of a hullaccording to this invention avoids the costs normally associated withthe bending operations required by prior hull designs.

Considering now the plating fitted to the frames, it will be apparentthat the plates 40, FIG. 3, required for the lower frame members fromstations 0-6 are all identical. This is because the spacing and rotationbetween any pair of consecutive frames is identical; or in other words,because equal longitudinal increments of a helical or screw surface areidentical. As will readily be appreciated, this feature of the inventiongreatly reduces the cost of fabricating and tting the bow plates.Whereas such plates heretofore were individually shaped, often tocompound curved surfaces, and individually fitted to the frames, in thepractice of this invention the plates 40 are fabricated by massproduction, and fitted at random. The plates 40 are slightly keystoneshaped, inasmuch as the distance between adjacent frames increases fromthe keel upwards, due to the rotation of the frames about the keel. Theplates 40 are preferably bent or warped a slight amount to form acontinuously curved helical surface, although the plates alternativelymay be left flat to form a close approximation to a helical surface. Theplates 42, FIG. 4, for the lower fratrie members from stations 14-20 aresimilarly shaped, although they are of decreasing lengths.

The plates 44 and 46 for the upper members of the frames from stations 06 and 14-20, respectively, are slightly cylindrical, or at if such issuitable.

From stations 6-14, the middle body of the hull, the bottom plates 48are all fiat and identical, and the side plates '50 are also fiat andidentical.

It will be apparent from the foregoing that the fabrication and fittingof the plates for the hull of this invention is greatly simplified overthe corresponding operations for the hulls of the prior art.

The middle body of this invention will be recognized as being parallel,and rectangular in cross section. In addition to being economical toconstruct, such middle body also provides a maximum cargo volume that isespecially adapted to carrying modern containerized cargo.

As stated previously, the present ships hull is also an efficient hull,because the helical bow and stern surfaces 34, 36 smoothly merge intothe at under portion of the middle body. This can be seen from thesmooth rotation of the V-angles of line 0 6 from about 0 to about 80,and the smooth decrease of the V-angles of lines 14-20 from about 180towards 0. Moreover, the helical bow and stern portions 34, 36 of thehull tend to turn the displaced water and guide it smoothly under theship, in the manner of a screw, thereby minimizing the wave makingresistance of the ship.

It will now be clear that the hull of this invention is both economicalto construct and operate, thus resulting in a total savings over thelifetime of the ship. The hull is especially suited to medium speedcargo ships such as feeder ships, coastal ships, tankers, bulk carriersand the like.

While the invention has been described and its features explained withreference to a single preferred illustrative embodiment thereof, it isto be understood that the invention is not limited to all the detailsincluded for illustration, but only as set forth in the appended claims.

I claim:

l. A ships hull comprising:

a plurality of frames lhaving straight [vertical] upper members andV-shaped lower members,

the V-angles of consecutive frames from the stem aft increasing by afirst constant angular increment from about 0 to about 180, remaining atsaid about 180 for one or more frames, and then decreasing by a secondconstant angular increment from said about 180 towards 0,

whereby said hull was helical bow [surfaces, a flat middle body undersurface, helical] and stern surfaces and vertical side surfaces] 2. Aships hull as set forth in claim 1, wherein said frames having saidincreasing and said about 180 V- angles are joined along a horizontalkeel, said lower V-shaped members of said last-mentioned frames beingequal in length.

3. A ships hull as set forth in claim 2, wherein said frames having saiddecreasing V-angles are joined along a sloped after keel.

4. A ships hull as set forth in claim 3, wherein said second constantangular increment is different from said first constant angularincrement.

5. A ships hull as set forth in claim 4, wherein said frames having saiddecreasing V-angles terminate in a flat transom stern.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

FOREIGN PATENTS 120,467 ll/l9l8 Great Britain.

ANDREW H. FARRELL, Primary Examiner UNITED STATES PATENT OFFICECERTIFICATE 0F CORRECTION Patent No. Rel 26 I,909 Dated June 9 1970Inventor(s) Mario I. Andrea It is certified that error appears in theabove-identified patent and that said Letters Patent are heeby eorectedas shown below:

Column l, lines 19 and 5C! "to" should read -2. Column 2, line 1l,"steam" should read stem. Column 3, lin 34, "O" (second ocsurfence)should read O line 35,

"8O should read --180 Column 4, line i8, "was" should read "has".

SEMES ND SEAlD sJEPzQ 19m A mlm E. BGEUYIIER, JR. nesting Officeronnnissicuwz` of Patmt

